A frequent area of use of generic quick-change tool holder systems is their use in machines for ground preparation, especially in road construction. This frequently involves machines having a driven roller rotatable about a horizontal axis, on which a plurality of ground preparation tools, in particular cutting tools and especially round-shank picks, are arranged. Such machines comprise, for example, stabilisers, recyclers and road millers, in particular cold millers. During working operation, the holders for receiving the cutting tools, in particular round-shank picks, are exposed to high stress levels and extremely high wear, on the one hand due to the broken material in the milling box and on the other hand due to the rotating round-shank pick, in particular in the area of the tool shank receiving bore in the tool holder and the contact surface of a wear disk which is possibly provided. Furthermore, the tool holder becomes worn or destroyed when the tool breaks off, falls out or is worn down. In order to be able to renew the worn or destroyed components of the tool holder easily and rapidly, the use of so-called quick-change tool holder systems has become established.
The essential components of such a quick-change tool holder system are a base part and a quick-change tool holder connected to the base part, which is configured for receiving a tool for ground preparation, for example, a cutting tool, in particular a round-shank pick. The base part is fastened firmly on the cylindrical outer surface of the milling roller which is usually mounted horizontally and perpendicular to the working direction of a corresponding construction machine, for example, by firmly welding the base part on the roller body. The base part therefore forms the element linking the quick-change tool holder system to the roller base body. The base part is further used for mounting the quick-change tool holder system or is configured for mounting the quick-change tool holder system. To this end, a quick-change tool holder receptacle is provided in the base part, which for example can comprise a suitable receiving bore in the usually compactly configured base part. The quick-change tool holder also comprises a comparatively compact element. The quick-change tool holder can be reversibly mounted on the base part and for this reason, for example, has corresponding threads, clamping pins and/or screw holes, etc. A defective quick-change tool holder can therefore be exchanged rapidly, without needing to separate the base part from the roller body for this purpose. The quick-change tool holder is further configured for receiving the cutting tool, in particular a round-shank pick, and for this purpose has a corresponding tool receptacle, for example a cutting tool receptacle in the form of a cylindrical receiving channel provided for receiving and mounting the cutting tool. Round-shank picks are frequently mounted rotatably about their cylinder axis in the quick-change tool holder and are secured against any axial displacement by suitable clamping means, for example, a clamping sleeve. The advantage of the quick-change tool holder system is that in the event of a defective tool, it is possible to selectively replace the tool and/or the quick-change tool holder without the fixed connection of the base part to the roller body needing to be expensively released and then remade again.
Although generic quick-change tool holder systems have in principle already proved successful, there is still need for improvement. This relates in particular to exchanging the machining tool and/or the quick-change tool holder and the robustness of the entire quick-change tool holder. It is therefore the object of the present invention to provide a quick-change tool holder system that enables an easier exchange of the quick-change tool holder on the base part and at the same time has an increased robustness.